Heat a nonstick skillet coated with cooking spray over medium heat. Add chicken, and sauté 2 minutes. Remove chicken from pan. (Kiy Note: I tend to use leftover chicken, but I have done this in a pinch.)

Pour rice vinegar mixture into pan, and bring to a boil over medium-high heat. Cook mixture 6 minutes or until slightly thickened. Return chicken to pan; cook 1 minute or until chicken is done. (Mixture will be consistency of thick syrup.)

Sprinkle cheeses over prepared crust, leaving a 1/2-inch border, and top with chicken mixture. Bake at 500° for 12 minutes on bottom rack in oven. Sprinkle with green onions. Place pizza on a cutting board; let stand 5 minutes.